The hammer of a typical hand-held firearm is secured in a cocked position through engagement of the hammer with a component such as the bar or trigger. The hammer is generally held in the cocked position via an engaging projection that is formed in the lower portion of the hammer. If the weapon should accidentally fall to the ground, then forces act on the component securing the hammer. These forces can lift the securing component (typically, against the force of a retaining spring), out of the projection so that the hammer is released and a shot is then triggered unintentionally.
Many proposals have been made in order to make trigger and safety devices more effective and secure. (See, for example, U.S. Pat. No. 3,962,809.) Many of these proposals are entirely effective, but are also complicated. For example, it is known to block or lift the striking spring out of the motion path of the hammer if the trigger is not pulled. However, these known devices have sliding parts which, in the case of dirty, unlubricated, or rusted weapons, are sluggish, and therefore make the pulling of the trigger to fire a shot difficult.
Furthermore, many safety parts are stressed to the point of bending, and can even possibly break. For example, even the engaging projection of the hammer could break off. If hammers of plastic are used instead of steel hammers, as was recently normally the case, then access to the centuries of materials expertise available to steel hammers is lost and a very improbable event in the context of steel hammers (namely, hammer part breakage), must be taken into consideration.
A swiveling lever has been shown in U.S. Pat. No. 5,225,612. The lever of the '612 Patent serves as a magazine safety unit and can be stressed in the safety position by the guide bar of the striking spring if the hammer of a self-loading pistol is clamped without a magazine having been inserted. However, this swiveling lever is not stressed in the direction of its transverse axis, but is instead swiveled at an angle to this axis against a stationary construction on which it is supported in a stable manner.
A safety device in which an eccentric shaft projects out, upon rotation, over the rear end of the firing pin and, thus, receives the striking hammer, is already known. Fine particulate matter that sprays through the weapon can, however, cause a particle to be caught behind the firing pin. In such circumstances, the particle passes the impact of the hammer along to the firing pin through the eccentric shaft.
U.S. Pat. No. 4,352,317 is also relevant prior art as explained below.